sir I am unable to understand this code .
can you exp;ain
#include
using namespace std;
int a[1000000], l[1000000], r[1000000];
int main()
{
int n, i, j;
cin >> n;
for (i = 0; i < n; i++)
{
cin >> a[i];
}
l[0] = a[0];
r[n - 1] = a[n - 1];
int leftmax = 0, rightmax = 0;
for (i = 1; i < n; i++)
{
l[i] = max(l[i - 1], a[i]);
}
for (i = n - 2; i >= 0; i–)
{
r[i] = max(r[i + 1], a[i]);
}
int water = 0;
for (i = 0; i < n; i++)
{
water += (min(l[i], r[i]) - a[i]);
}
cout << water;
return 0;
}